Information reproducing apparatus, method of correcting reproducing program, and information recording medium

ABSTRACT

An information reproducing apparatus, in which a disk having correction data recorded thereon is placed, acquires region information indicative of a region corresponding to the correction data after load processing is performed by a ROM loader. Then, under the control of a CPU, the apparatus determines the correction data to be used for correcting a reproducing program based on the region information, reads the correction data from a lead out area or its outer region on the disk, temporarily retains the read correction data in a first RAM or a second RAM, and then stores the correction data to be resident in a nonvolatile first flash memory or a second flash memory, to correct the reproducing program based on the correction data. The information reproducing apparatus thereafter reproduces user data recorded on the disk according to the corrected reproducing program.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to an information recordingmedium such as an optical disk on which various content objects arealready recorded and an information reproducing apparatus thatreproduces such content objects from the information recording medium.More particularly, the invention is directed to a method of correcting areproducing program executed by the information reproducing apparatususing correction data recorded on the information recording medium.

2. Description of Related Art

Prior-art optical disk players that play an optical disk such as a DVDon which various content objects are already recorded sometimesencounter, after shipped from factories, trouble caused by bugs in theirplaying program. A user facing such trouble when trying to play a DVD onhis or her optical disk player contacts the maker of the optical diskplayer to have the player troubleshooted so that the maker will takeeffective measures to fix the trouble. It usually takes a considerabletime before the optical disk player is fixed, to both the user's andmaker's disadvantage, probably more to the maker's disadvantage in thatthe maker has to accommodate similar complaints from many users spendingits time and money. In addition, trouble likely to be encountered bythese optical disk players tends to become increasingly complicated dueto differences in content data, incompatibility among variousspecifications and standards, and problems associated with authoringtools, etc., to such an extent that a drastic measure seems difficult.

Under such circumstances, JP-A-7-85638 proposes one solution toeliminate trouble such as mentioned above. In this solution, patch datafor the playing program is produced, then an optical disk isdistributed, on which the generated patch data is recorded in itspredetermined area so that an optical disk player reads the recordedpatch data to correct its playing program. This solution permits theoptical disk player to automatically correct its playing program uponplacing of the optical disk in the optical disk player.

However, in view of the fact that such trouble is often caused due tooptical disk players being available in a diversity of models, it isnecessary to prepare a plurality of types of correction data compatiblewith different models of optical disk players. Therefore, it isdesirable that the plurality of types of correction data are recorded onan optical disk. To record the plurality of types of correction data onan optical disk, a sizable area needs to be reserved on the opticaldisk. However, the data size usable in a lead-in area is so limited thatit is difficult to record the plurality of types of correction data tosuch an extent as to take care of trouble associated with a diversity ofplaying programs.

SUMMARY OF THE INVENTION

The invention has been made to satisfy the above need. It is, therefore,an object of the invention to provide an information reproducingapparatus, a method of correcting a reproducing program, and aninformation recording medium which upon occurrence of trouble in thereproducing program, are capable of correcting the reproducing programquickly and properly based on a plurality of types of correction datacorresponding to different reproducing programs which are dependent upondifferent models, etc. of information reproducing apparatuses.

The above object of the present invention can be achieved by aninformation reproducing apparatus of the present invention that correctsa reproducing program using correction data recorded on an informationrecording medium to reproduce record information recorded on theinformation recording medium. The apparatus is provided with: acorrection control device for reading the correction data to be used tocorrect the reproducing program, from the information recording mediumon which the correction data is recorded in a lead out area, to correctthe reproducing program based on the read correction data; and areproduction control device for reproducing the record informationrecorded on the information recording medium according to a latestversion of the reproducing program which is corrected by the correctioncontrol device.

According to this invention, if the information reproducing apparatusencounters trouble associated with the reproducing program whenreproducing the record information recorded on the information recordingmedium, the information reproducing apparatus reads the correction datafrom the lead out area of the information recording medium to correctthe reproducing program using the read correction data, so that theinformation reproducing apparatus can thereafter reproduce theinformation recording medium using the latest version of the reproducingprogram. Thus, for trouble associated with the reproducing program to beexecuted by the information reproducing apparatus, the maker of theinformation reproducing apparatus no longer needs to recall its productto reduce its cost and time that would otherwise be incurred for fixingthe trouble. The user can also stop worrying about correction to his orher advantage. In addition, the correction data is recorded in the leadout area in which a larger size can be reserved therefor than in thelead in area where various control information is usually recorded, sothat various types of correction data can be used to properly correctdifferent reproducing programs dependent upon different informationreproducing apparatuses.

The above object of the present invention can be achieved by aninformation reproducing apparatus of the present invention that correctsa reproducing program using correction data recorded on an informationrecording medium to reproduce record information recorded on theinformation recording medium. The apparatus is provided with: acorrection control device for reading the correction data to be used tocorrect the reproducing program, from the information recording mediumon which the correction data is recorded in an area radially outward ofa lead out area, to correct the reproducing program based on the readcorrection data; and a reproduction control device for reproducing therecord information recorded on the information recording mediumaccording to a latest version of the reproducing program which iscorrected by the correction control device.

According to this invention, the reproducing program can be correctedusing the correction data recorded in an area radially outward of thelead out area, in a similar configuration to the above invention. Thus,various types of correction data can be used to properly correctdifferent reproducing programs dependent upon different informationreproducing apparatuses in accordance with operations and advantagescommon to the above invention.

In one aspect of the present invention, the information reproducingapparatus is further provided with a nonvolatile storage device forstoring the correction data, wherein the correction control devicerecords the correction data in a predetermined location of the storagedevice, and the reproduction control device executes a corrected versionof the reproducing program after confirmation that the correction datais recorded normally.

According to this aspect, upon locating the correction data on theinformation recording medium, the information reproducing apparatusrecords the correction data at a predetermined position of thenonvolatile storage device, and executes the corrected version of thereproducing program after confirmation that the correction data isnormally recorded. Thus, once the reproducing program is corrected basedon the correction data, the information reproducing apparatus allows thecorrected version of the reproducing program to reside in thenonvolatile storage device, and hence the information reproducingapparatus can automatically execute the corrected version of thereproducing program thereafter without involving any complicatedcontrol.

In another aspect of the present invention, the correction controldevice records a start position of the correction data as a startposition address, and the reproduction control device executes thecorrected version of the reproducing program by searching the startposition address.

According to this aspect, when recording the correction data in thenonvolatile storage device, the information reproducing apparatusrecords a start position address corresponding to the head of thecorrection data, to use the recorded start position address forexecution of the corrected version of the reproducing program. Thus, theposition where the correction data is recorded can be accuratelylocated, to allow the reproducing program to be executed reliably.

In further aspect of the present invention, while the correction data isrecorded in the storage device, an operation of turning off power isprohibited.

According to this aspect, the information reproducing apparatus isprohibited from being turned off during the recording of the locatedcorrection data in the nonvolatile storage device. This arrangement thusprevents destruction of the corresponding type of correction data due toinadvertent turning off of the power of the information reproducingapparatus.

In further aspect of the present invention, the correction data isprovided with difference data between an original version of thereproducing program and a corrected version of the reproducing program,and the correction control device corrects the reproducing program basedon the original version of the reproducing program and the differencedata.

According to this aspect, once the information reproducing apparatuslocates the correction data on the information recording medium, acorrected version of the reproducing program can be obtained from thecorrection data given as difference data and the original version of thereproducing program. Thus, the size of the correction data can bereduced, to leave the size of user data unreduced.

The above object of the present invention can be achieved by a method ofthe present invention of correcting a reproducing program usingcorrection data recorded on an information recording medium. The methodis provided with: the process of reading the correction data to be usedto correct the reproducing program, from the information recordingmedium on which the correction data is recorded in a lead out area; andthe process of correcting the reproducing program based on the readcorrection data.

According to this aspect, the reproducing program requiring measures toeliminate trouble can be corrected based on the correction data, bysimilar operations to the above invention. Thus, various types ofcorrection data can be used to properly correct different reproducingprograms dependent upon different information reproducing apparatuses.

The above object of the present invention can be achieved by a method ofthe present invention of correcting a reproducing program usingcorrection data recorded on an information recording medium. The methodis provided with: the process of reading correction data to be used tocorrect the reproducing program, from the information recording mediumon which the correction data is recorded in an area radially outward ofa lead out area; and the process of correcting the reproducing programbased on the read correction data.

According to this invention, the reproducing program requiring measuresto eliminate trouble can be corrected based on the correction data, bysimilar operations to the above invention. Thus, various types ofcorrection data can be used to property correct different reproducingprograms dependent upon different information reproducing apparatuses.

In one aspect of the present invention, the method is provided with: theprocess of recording the correction data at a predetermined position ofa nonvolatile storage device; and the process of recording a startposition of the correction data as a start position address.

According to this aspect, the correction data is allowed to reside inthe nonvolatile storage device for subsequent effective use withoutinvolving any complicated control, by similar operations to the aboveinvention.

In another aspect of the present invention, the correction data isprovided with difference data between an original version of thereproducing program and a corrected version of the reproducing program,and the reproducing program is corrected based on the original versionof the reproducing program and the difference data.

According to this aspect, the size of the correction data as thedifference data can be reduced, by similar operations to the aboveinvention.

The above object of the present invention can be achieved by aninformation recording medium of the present invention on which recordedinformation as well as correction data for correcting a reproducingprogram executed by an information reproducing apparatus are recorded,wherein the correction data is recorded in a lead out area.

According to this invention, the correction data are recorded in thelead out area of the information recording medium to correct thereproducing program by using the correction data as mentioned above.Thus, different reproducing programs can be corrected as the informationrecording medium encounters such different reproducing programs when puton a general distribution channel, to both the user's and maker'sadvantage.

The above object of the present invention can be achieved by aninformation recording medium on which recorded information as well ascorrection data for correcting a reproducing program executed by aninformation reproducing apparatus are recorded, wherein the correctiondata is recorded in an area radially outward of a lead out area.

According to this invention, the correction data are recorded in an arearadially outward of the lead out area of the information recordingmedium to correct the reproducing program by using the correction dataas mentioned above. Thus, different reproducing programs can becorrected as the information recording medium encounters such differentreproducing programs when put on a general distribution channel, to boththe user's and maker's advantage.

In one aspect of the present invention, the correction data is recordedin a recording format different from a recording format in which therecorded information is recorded.

According to this aspect, the user data and the correction data arerecorded on the information recording medium in different data formats,respectively. This arrangement thus prevents any third party fromabusing the correction data by making it hard to analyze the correctiondata or by encrypting the correction data, for example.

In another aspect of the present invention, the correction data eachcomprises difference data between an original version of the reproducingprogram and a corrected version of the reproducing program.

According to this invention, the correction data are recorded in theform of difference data which is small in size, by similar operations tothe above invention. Thus, an information recording medium having anunreduced user data storage area can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing major parts of an optical disk playeras an information reproducing apparatus to which the invention isapplied;

FIG. 2 is a diagram schematically showing the data structure of a diskplaced in the optical disk player;

FIG. 3 is a first flowchart showing a process of correcting a playingprogram, performed by the optical disk player;

FIG. 4 is a second flowchart showing the process of correcting theplaying program, performed by the optical disk player;

FIG. 5 is a diagram showing the structure of a correction data tableread in step S22 of FIG. 4; and

FIG. 6 is a diagram showing the sector format of a DVD.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A preferred embodiment of the invention will now be described withreference to the drawings. The preferred embodiment refers to the casewhere the invention is applied to an optical disk player as aninformation reproducing apparatus that plays an information recordingmedium on which data are already recorded.

Referring to FIG. 1, the optical disk player, in which a ROM disk 10 asa read-only information recording medium is placed to play user datacorresponding to content, is generally provided with a pickup 11, a datademodulator 12, an MPEG demodulator 13, an NTSC video modulator 14, aCPU 15, a ROM loader 16, a first RAM 17, a second RAM 18, a first flashmemory 19, and a second flash memory 20.

Referring then to FIG. 2, the data structure of the disk 10 placed inthe optical disk player will be described. The disk 10 is marketed withdata already recorded thereon, the data being MPEG or similarly codeddata corresponding to content such as, for example, films. As shown inFIG. 2, the disk 10 has three recording areas, i.e., a lead-in area, auser data area, and a lead-out area laid out from the inner toward theouter side.

The lead-in area includes cryptographic information used to encrypt thecontent for copyright protection, and disk information indicative of thephysical characteristics of the disk 10. The user data area includesfile system information indicative of the data structure for recordingthe content by conversion into files, navigation information used todisplay menus and sequences necessary for playback control, and userdata such as video/audio data corresponding to the body of the contentalready recorded at the factory. The lead-out area defines the end ofthe data recorded on the disk 10.

On the disk 10 according to this embodiment, the correction datanecessary for correcting a playing program in the optical disk player isalready recorded. Specifically, in order to take care of troubleassociated with the optical disk player in playing a specific contentobject, correction data are embedded in the disk 10 in a manner usableby the optical disk player. While the correction data may be embedded inany of the lead-in area, user data area, lead-out area and outer regionof the lead-out area, the following description refers to the case ofembedding the correction data in the lead-out area or its outer region.How the playing program is corrected using the correction data by theoptical disk player will be described below.

Referring back to FIG. 1, the pickup 11 irradiates a recording track ofthe rotating disk 10 with an optical beam through optics, and alsoreceives reflected light from the information recorded surface of thedisk 10 to output photoelectrically converted read signals.

The data demodulator 12 subjects the received read signals from thepickup 11 to signal processing including waveform shaping, demodulation,and analog-to-digital conversion, to output digital signalscorresponding to the content. The demodulator 12 also outputs theabove-mentioned correction data, which is required to correct theplaying program as will be described below.

The MPEG demodulator 13 demodulates the digital signals demodulated bythe data demodulator 12, in a manner compatible with an MPEG format toseparately generate video and audio data outputs corresponding to thecontent. The video data output is fed to the NTSC video modulator 14 togenerate an NTSC-compatible video output for an external device. Theaudio data, which is generated as stereophonic L/R signals, is alsooutput to an external device.

The CPU 15 performs general control over the operations of the opticaldisk player shown in FIG. 1. The CPU 15 is coupled to various memorymeans and the ROM loader 16 via a data bus. The memory means usable bythe CPU 15 are the first and second RAMs 17 and 18 for temporarilyretaining data, and the first and second flash memories 19 and 20 asnonvolatile memories. The CPU 15 serves as a correction control deviceand a reproduction control device of the invention in cooperation withother components.

The ROM loader 16 performs load processing under the control of the CPU15 prior to playing the disk 10 loaded in the optical disk player. Atthe playing start, the ROM loader 16 loads, to the first or second RAM17 or 18, the playing program to be finally stored in the first orsecond flash memory 19 or 20.

The first and second RAMs 17 and 18 are volatile memory devices used bythe CPU 15 for its control processing, and temporarily retain theplaying program, which needs to be loaded every time the optical diskplayer is turned on. In contrast, the first and second flash memories 19and 20 are nonvolatile memory devices used to make resident therein theplaying program temporarily retained in the first and second RAMs. Thus,even when the optical disk player is tuned off or even when the data inthe first and second RAMs 17 and 18 are deleted, the playing program canbe retained in the first and second flash memories 19 and 20.

It should be appreciated that a dual configuration comprising a pair ofRAM-flash memory systems is proposed in this embodiment in order toimplement correction of the playing program. Briefly, while the memorydevice in one of the pair of RAM-flash memory systems is executing theplaying program, the memory device in the other system stores acorrected version of the playing program, which is corrected using thecorrection data recorded on the disk 10. This configuration will bedescribed in more detail below.

Referring next to FIGS. 3 and 4, a process of correcting the playingprogram, performed by the optical disk player according to thisembodiment will be described. The process shown in FIG. 3 starts whenthe optical disk player is turned on. First, whether or not the disk 10is placed in the optical disk player is determined (step S11). If so(“YES” in step S11), the disk 10 is driven to rotate (step S12).

Then, a focus servo is activated (step S13). Upon confirmation that thefocus servo loop is closed to be locked (“YES” in step S14), a trackingservo is then activated (step S15). Successively, upon confirmation thatthe tracking servo loop is closed to be locked (“YES” in step S16), therpm of the disk 10 is checked (step S17). If the rpm has reached apredetermined value after a predetermined time has elapsed (“YES” instep S17), then the head of the disk information is searched in order toread various information recorded in the lead in area of the disk 10(step S18).

If it is not confirmed that the focus servo is locked (“NO” in stepS14), if it is not confirmed that the tracking servo is locked (“NO” instep S16), or the rpm has not reached the predetermined value after thepredetermined time has elapsed (“NO” in step S17), the process of FIG. 3proceeds to an abnormal end routine.

Referring next to FIG. 4, if it is determined that the disk 10 hascorrection data based on information read in step S18 (“YES” in stepS19), then a disk ID as an identifier contained in the disk informationis read from the lead in area (step S20). Otherwise (“NO” in step S19),the process of FIG. 4 is brought to an end.

Successively, if it is determined that the playing program in theoptical disk player has never been corrected by a type of correctiondata corresponding to the disk 10 based on the disk ID read in step S20(“NO” in step S21), then the start address of a correction data tablelocated in a predetermined area of the disk 10 is searched to read thecorrection data table (step S22). If, on the other hand, the playingprogram has been corrected by the corresponding type of correction data(“YES” in step S21), then the process of FIG. 4 is brought to an end.

Referring here to FIG. 5, the correction data table contains, asinformation relevant to the type of correction data corresponding to thedisk 10 to be read in step S22, a company name, a product ID No., acorrection data version, a corresponding region, a correction data startaddress, and a correction data size. Thus, based on the correction datatable, information unique to the disk 10 and information relevant to thetype of correction data corresponding to the disk 10 can be identified.It should be noted that the correction data table contains as manycorrection data start addresses, correction data sizes, etc. as aplurality of types of correction data which are recorded to fix troubledependent upon different models, etc. of optical disk players.

In this embodiment, the company name, product ID No. and correction dataversion contained in the correction data table are compared with thecompany name, product ID No. and playing program version stored in theoptical disk player to make a first determination as to whether or notcorrection is necessary (step S23). If these items of information in theoptical disk player do not match the equivalents on the disk 10 (“NO” instep S23) so that no correction is necessary, the process of FIG. 4 isterminated immediately. If the first determination indicates thatcorrection is necessary (“YES” in step S23), then the “correspondingregion” contained in the correction data table of the disk 10 iscompared with regional information about where the optical disk playeris sold which is stored in the optical disk player to make a seconddetermination as to whether or not correction is necessary (step S24).Specifically, the “region” corresponding to the corresponding type ofcorrection data, not “region” corresponding to a specific content objecton the disk 10 itself, serves as the basis for determining necessity ofcorrection in terms of “regional aspects” of the playing program to becorrected. The “corresponding region” corresponding to the correspondingtype of correction data on the disk 10 helps determine necessity ofcorrection in order to eliminate trouble associated with factorssuggestive of region such as the model of a particular maker and thelanguage of a particular country, for example. This multi-stagedetermination configuration narrows the aspects of the trouble to befixed by correction down to the “region” specified by the “correspondingregion” in order to obviate wasteful correction.

If the regional aspect of the optical disk player does not match thecorresponding region through the second determination (“NO” in stepS24), then the process of FIG. 4 is immediately terminated. Otherwise(“YES” in step S24), various operations such as turning off the opticaldisk player and giving user commands are prohibited (step S25).Successively, the corresponding correction data is read from the leadout area or its outer region on the disk 10, and the read correctiondata is recorded in the second RAM 18 and the second flash memory 20(step S26). The prohibition of various operations in step S25 is toprevent abnormality from occurring during the reading and recording ofthe correction data in step S26.

In step S26, the correction data start address and correction data sizecontained in the correction data table are read, and the start addressis then searched to read a predetermined size of the corresponding typeof correction data. Thereafter, the corresponding type of correctiondata which has been read is developed in both the volatile second RAM 18and the nonvolatile second flash memory 20.

It is desirable here that the correction data according to thisembodiment be recorded on the disk 10 in a format different from that ofthe user data. If the correction data were recorded using the sameformat as that of the user data, the correction data could be easilyread, analyzed, copied, and distributed. In order to prevent thecorrection data-recorded disk 10 from being delivered to any willfulthird party, it is required that a recording format different fromtypical recording formats be used in recording the correction data tokeep anyone from accessing the correction data. The correction data mayalternatively be encrypted upon recording on the disk 10.

The correction data according to this embodiment can be embedded aswatermarks in the video and audio data corresponding to the user data.For example, it may be effective to embed correction data for fixingtrouble associated with a particular one of a plurality of contentobjects, in the video and audio data of any of the content objects otherthan that particular content object as a watermark. This techniquepermits such correction data to be read during the playing of thewatermarked content object based on the watermark to correct the playingprogram. This technique, which would make it harder for anyone to locatecorrection data by embedding the correction data in user data which islarge in size, is effective in protecting correction data.

The correction data according to this embodiment may be used to directlyrecord a corrected playing program, i.e., replacing an entire originalplaying program with a corrected playing program, or record onlydifference data between an original playing program and a correctedplaying program. In the difference data approach, the corrected playingprogram needs to be generated using both the difference data indicatedby the correction data and the original playing program. The differencedata approach is more advantageous over the entire recording approach inreducing the size of the correction data.

Next, if it is determined that the reading and recording have beencompleted normally in step S26 (“YES” in step S27), a start positionaddress is changed (step S28). The start position address is given toindicate the head of a playing program corresponding to thecorresponding type of correction data, and recorded in a predeterminedarea of the first flash memory 19 or the second flash memory 20, forexample. Thus, by referring to the start position address changed instep S28, the start position for executing the playing program correctedby the corresponding type of correction data can be located.

Alternatively, a flag indicating that the recording has been performednormally may be appended to the start of the playing programcorresponding to the corresponding type of correction data, instead ofchanging the start position address in step S28. In this case, the flagshould be detected to locate the start position for executing thecorrected playing program.

Successively, if the playing program has been corrected normally by theabove process (“YES” in step S29), then the prohibition of the variousoperations in step S25 is cancelled (step S30), so that the optical diskplayer will be ready to accept the operations such as turning off thepower and giving user commands. Additionally, the disk ID is stored in amemory within the CPU 15 so that the above correcting process will notbe repeated on the disk 10 (step S31). In this way, the process of FIGS.3 and 4 are brought to a normal end.

If, on the other hand, the reading and recording have not been completednormally in step S26 (“NO” in step S27), then the process branches tothe abnormal end routine. If the playing program has not been correctednormally (“NO” in step S29), the process resets the start positionaddress to the last address before the change in step S28 (step S32),and then proceeds to the abnormal end routine.

When the process of FIGS. 3 and 4 have been terminated normally, thecorrected playing program is recorded in the second RAM 18 and thesecond flash memory 20. From then on, the optical disk playercontinuously plays the disk 10 using the corrected playing programstored in the volatile second RAM 18. Furthermore, once the optical diskplayer is turned off, the user can load the corrected playing programresident in the nonvolatile second flash memory 20 using the ROM loader16 to play the disk 10. To further correct the corrected playing programunder this condition, another corresponding type of correction dataneeds to be recorded in the first flash memory 19 in step S26 since thepreviously used type of correction data is resident in the second flashmemory 20. That is, in the above process, every time the playing programis corrected, the latest corrected version of the playing program isstored alternately in the first flash memory 19 and the second flashmemory 20 to be resident therein.

It should also be appreciated that even if any abnormality, such assudden interruption of power during the reading of the correspondingtype of correction data in step S26, has occurred to cause failure innormal reading, this will create no problem in the next playback. Inthis case, the start position address will not be changed in step S28 sothat the disk 10 can be played normally using the original playingprogram recorded in one of the pair of RAM-flash memory systems.

Here, the location where the correction data is recorded on the disk 10according to this embodiment will be described. As mentioned above, itis assumed in this embodiment that the correction data is to be recordedin the lead out area or its outer region on the disk 10. For example, ina DVD format, the innermost and outermost radii of the lead out areafollowing the user data area are specified, and the lead out area can beidentified by referring to a “last recorded address” which is recordedin the lead in area.

Referring now to FIG. 6, a sector, which is a basic data unit of a DVD,consists of an array of 172 bytes by 12 rows. Recorded at the head ofthe sector are: sector information including a sector number, an areatype, a data type, and a layer number; a parity IED for detecting sectornumber error; and a flag reserved in the sector. The lead out area islocated by referring to the area type. At the tail of the sector whichfollows the main data, a parity EDC for detecting error throughout thesector is appended.

It is specified that zeroes are to be written as main data in sectorsbelonging to the lead out area. However, in this embodiment in which thecorrection data is to be recorded in the lead out area, a data patterncorresponding to the correction data is written, instead of zeroes, insuch sectors. There will be no trouble recording the correction data inthe lead out area because the data written in the lead out area wouldnever be referred to for any other purpose than for reading thecorrection data. It should be noted that the correction data written inthe sectors belonging to the lead out area is identified by appending apredetermined header at the head of the lead out area, or,alternatively, the reserved flag mentioned above may be used for thesame purpose.

In another embodiment, the correction data may be recorded in apredetermined location in the outer region of the lead out area. In thisembodiment, a flag indicative of the correction data recording areaneeds to be appended, so that the correction data recording area can belocated by referring to that flag.

As mentioned above, the correction data may be recorded in the lead outarea or its outer region on the disk 10 no matter how the lead out areais arranged, variable or fixed.

A modification of the above embodiment will be described as a case wherethe invention is applied to an information recording/reproducingapparatus. Specifically, an optical disk recorder as the informationrecording/reproducing apparatus performs recording on a recordable disk10. In this case, correction data for correcting a recording/playingprogram executed by the optical disk recorder are recorded on the disk10. A basic flow of correcting process steps performed by the opticaldisk recorder is generally common to that performed by the optical diskplayer described above. As to the recordable disk 10, due to its being ablank disk, correction data to be recorded is relevant to troubleassociated with the recording/playing program inherent in the opticaldisk recorder, not relevant to trouble associated with a particularcontent object.

Various physical configurations may be conceivable to record suchcorrection data on the recordable disk 10. For example, in oneconfiguration, each of recording tracks alternates with each of wobblingguide tracks in the radial direction, to record user data on therecording tracks and extract a rotation reference signal from the guidetracks. In this configuration, the correction data is modulated alongthe guide tracks during the formation of the guide tracks, so that thecorrection data can be extracted during playback. This configurationprevents any willful third party from tampering the correction data onthe disk 10.

It should be noted that if the recordable disk 10 is a DVD, the opticaldisk recorder uses a push-pull method for tracking, so that thecorrection data is extracted from push-pull signals. That is, thecorrection data on the recordable disk 10 can be read by a methoddifferent from a DPD method typically used by a DVD optical disk player,and hence enhanced security can be provided.

For a DVD-based disk 10 in which information pits are formed in groovedtracks, correction data pits may be formed on land tracks to be read bythe push-pull method. In this case also, the correction data can be readby the method different from typical reading methods used by opticaldisk players.

The following describes the case where the correction data is recordedin the lead out area or its outer region on the disk 10 in advance in anapplication of the invention to the optical disk recorder. In therecordable disk 10, a lead out area is defined when content data isrecorded, and thus no lead out area has not yet been provided in anunrecorded disk 10. To record correction data on a disk in advance asmentioned above, one must keep in mind the following points.

That is, the correction data recording area may be set at apredetermined location in an area outward of the outermost location ofthe user data area, or a minimally required lead out area may be set ata predetermined location in an area outward of the outermost location ofthe user data area. The recording of the correction data should start atthe tail of content data recorded in the user data area, by which thelead out area can be defined with its start position defined. Since thelocation (address) of the correction data recording area or the lead outarea is identifiable beforehand as mentioned above, the optical diskrecorder does not need to specify the address every time it reads andrecords the correction data to correct its playing program.

As described in the foregoing, according to the invention, theinformation reproducing apparatus reads correction data recorded in thelead out area or its outer region and corrects the reproducing programusing the read correction data, when reproducing an informationrecording medium. Thus, upon occurrence of trouble in the reproducingprogram for reproducing the information recording medium, thereproducing program can be corrected quickly and properly based on aplurality of types of correction data corresponding to differentreproducing programs compatible with different models, etc. ofinformation reproducing apparatuses.

The entire disclosure of Japanese Patent Application No. 2001-180695filed on Jun. 14, 2001 including the specification, claims, drawings andsummary is incorporated herein by reference in its entirety.

1. An information reproducing apparatus that corrects a reproducingprogram using correction data recorded on an information recordingmedium to reproduce record information recorded on the informationrecording medium, the apparatus comprising: a correction control devicefor reading the correction data to be used to correct the reproducingprogram, from the information recording medium on which the correctiondata is recorded in a lead out area, to correct the reproducing programbased on the read correction data; and a reproduction control device forreproducing the record information recorded on the information recordingmedium according to a latest version of the reproducing program which iscorrected by the correction control device, wherein the informationreproducing apparatus further comprises a nonvolatile storage device forstoring the correction data, wherein the correction control devicerecords the correction data in a predetermined location of the storagedevice, and the reproduction control device executes a corrected versionof the reproducing program after confirmation that the correction datais recorded normally.
 2. The information reproducing apparatus accordingto claim 1, wherein the correction control device records a startposition of the correction data as a start position address, and thereproduction control device executes the corrected version of thereproducing program by searching the start position address.
 3. Theinformation reproducing apparatus according to claim 1, wherein whilethe correction data is recorded in the storage device, an operation ofturning off power is prohibited.
 4. The information reproducingapparatus according to claim 1, wherein the correction data comprisesdifference data between an original version of the reproducing programand a corrected version of the reproducing program, and the correctioncontrol device corrects the reproducing program based on the originalversion of the reproducing program and the difference data.
 5. Aninformation reproducing apparatus that corrects a reproducing programusing correction data recorded on an information recording medium toreproduce record information recorded on the information recordingmedium, the apparatus comprising: a correction control device forreading the correction data to be used to correct the reproducingprogram, from the information recording medium on which the correctiondata is recorded in an area radially outward of a lead out area, tocorrect the reproducing program based on the read correction data; and areproduction control device for reproducing the record informationrecorded on the information recording medium according to a latestversion of the reproducing program which is corrected by the correctioncontrol device, wherein the information reproducing apparatus furthercomprises a nonvolatile storage device for storing the correction data,wherein the correction control device records the correction data in apredetermined location of the storage device, and the reproductioncontrol device executes a corrected version of the reproducing programafter confirmation that the correction data is recorded normally.
 6. Theinformation reproducing apparatus according to claim 5, wherein thecorrection control device records a start position of the correctiondata as a start position address, and the reproduction control deviceexecutes the corrected version of the reproducing program by searchingthe start position address.
 7. The information reproducing apparatusaccording to claim 5, wherein while the correction data is recorded inthe storage device, an operation of turning off power is prohibited. 8.The information reproducing apparatus according to claim 5, wherein thecorrection data comprises difference data between an original version ofthe reproducing program and a corrected version of the reproducingprogram, and the correction control device corrects the reproducingprogram based on the original version of the reproducing program and thedifference data.
 9. A method of correcting a reproducing program usingcorrection data recorded on an information recording medium, the methodcomprising: the process of reading the correction data to be used tocorrect the reproducing program, from the information recording mediumon which the correction data is recorded in a lead out area; and theprocess of correcting the reproducing program based on the readcorrection data, wherein the method of correcting a reproducing programfurther comprises: the process of recording the correction data at apredetermined position of a nonvolatile storage device; and the processof recording a start position of the recorded correction data as a startposition address which is used by the process of reading to search forthe corrected data.
 10. The method of correcting a reproducing programaccording to claim 9, wherein the correction data comprises differencedata between an original version of the reproducing program and acorrected version of the reproducing program, and the reproducingprogram is corrected based on the original version of the reproducingprogram and the difference data.
 11. A method of correcting areproducing program using correction data recorded on an informationrecording medium, the method comprising: the process of readingcorrection data to be used to correct the reproducing program, from theinformation recording medium on which the correction data is recorded inan area radially outward of a lead out area; and the process ofcorrecting the reproducing program based on the read correction data,wherein the method of correcting a reproducing program furthercomprises: the process of recording the correction data at apredetermined position of a nonvolatile storage device; and the processof recording a start position of the recorded correction data as a startposition address which is used by the process of reading to search forthe corrected data.
 12. The method of correcting a reproducing programaccording to claim 11, wherein the correction data comprises differencedata between an original version of the reproducing program and acorrected version of the reproducing program, and the reproducingprogram is corrected based on the original version of the reproducingprogram and the difference data.
 13. An information recording medium onwhich recorded information as well as correction data for correcting areproducing program executed by an information reproducing apparatus arerecorded, wherein the correction data is recorded in a lead out area,wherein the correction data each comprises difference data between anoriginal version of the reproducing program and a corrected version ofthe reproducing program.
 14. The information recording medium accordingto claim 13, wherein the correction data is recorded in a recordingformat different from a recording format in which the recordedinformation is recorded.
 15. An information recording medium on whichrecorded information as well as correction data for correcting areproducing program executed by an information reproducing apparatus arerecorded, wherein the correction data is recorded in an area radiallyoutward of a lead out area, wherein the correction data each comprisesdifference data between an original version of the reproducing programand a corrected version of the reproducing program.
 16. The informationrecording medium according to claim 15, wherein the correction data isrecorded in a recording format different from a recording format inwhich the recorded information is recorded.